🇺🇸 Made in America·100% U.S.-Based Team · 24+ Years in Cost Segregation
In 1997, a small team of tax attorneys for Hospital Corporation of America walked into the United States Tax Court in Washington. They were arguing about carpet. And lighting. And electrical panels. The IRS thought every one of those items was part of the building. HCA thought differently. HCA was about to win.
The ruling that came out of that case is called Hospital Corporation of America v. Commissioner. The citation is 109 T.C. 21. Almost no one outside specialized tax circles read it at the time. It is one of the most important real estate tax decisions of the last 60 years.
It is also the moment when cost segregation, as we know it today, became settled law. This is the story of how that happened.
To understand cost segregation, you have to go back to 1962. That year, Congress passed the Revenue Act of 1962, which created something called the Investment Tax Credit (ITC). The ITC let businesses deduct a percentage of the cost of certain qualifying property from their tax bill. Equipment qualified. Machinery qualified. Vehicles qualified. The basic building structure did not.
The IRS and taxpayers immediately started arguing about which items belonged in which bucket. Was the wiring in a factory part of the building (not eligible) or part of the equipment it supported (eligible)? Was the specialty lighting in a retail store part of the building or part of the merchandising fixtures? Was the dedicated electrical service running to a piece of manufacturing equipment part of the structure or part of the equipment?
The Treasury Department issued regulations. The Tax Court issued decisions. A body of case law slowly built up around the principle that certain components of a commercial building serve specific business functions rather than serving the building itself, and those components should be treated as tangible personal property for tax purposes rather than as real property.
This is the foundational legal concept underlying modern cost segregation. It is more than 60 years old. It is not a new strategy. It is not a loophole. It is the consistent application of a principle Congress wrote into the tax code in 1962.
The Economic Recovery Tax Act of 1981 changed the depreciation rules. The Accelerated Cost Recovery System (ACRS) replaced the older facts-and-circumstances approach with a system of standardized recovery periods. Property was assigned to specific classes (3-year, 5-year, 10-year, 15-year, etc.) based on the type of asset.
This was the moment when classifying property correctly became financially substantial. Under the old rules, the difference between depreciating a piece of property over 25 years versus 10 years was real but moderate. Under ACRS, with much faster recovery periods, the difference became dramatic. Property correctly classified as 5-year ACRS produced deductions over a fraction of the time of property classified as real property.
Cost segregation, as a specific engineering discipline, started developing in the early 1980s in response to ACRS. Engineering firms began offering studies that systematically identified which components of a commercial building qualified for shorter recovery periods. The studies relied on the body of case law that had developed since 1962, applied to specific buildings in specific industries.
The Tax Reform Act of 1986 was the most consequential tax legislation in modern American history. Among many other changes, it replaced ACRS with the Modified Accelerated Cost Recovery System (MACRS), which is still the governing depreciation framework today.
MACRS established the class lives still in use: 5-year property, 7-year property, 15-year property, 27.5-year residential rental property, and 39-year nonresidential real property. These are the categories every cost segregation study works with today. They have been the law for nearly 40 years.
The 1986 act also tightened the rules around what could be classified as personal property versus real property. The Tax Reform Act of 1986 codified, in significant detail, the principle that components of a commercial building serving specific business functions are tangible personal property, not real property. The act referenced and incorporated the Whiteco 6-factor test from a 1975 Tax Court case (Whiteco Industries v. Commissioner, 65 T.C. 664), which had been the framework for distinguishing personal from real property in tax contexts.
By the mid-1990s, cost segregation was a known strategy. Engineering firms were doing the studies. CPAs were claiming the deductions. The IRS was challenging them in audits.
The dispute that finally settled the legal status of cost segregation came from a hospital chain. Hospital Corporation of America had reclassified many components of its hospital buildings as tangible personal property for tax depreciation purposes. The IRS disallowed the classifications. HCA paid the additional tax and sued for refund.
The case went to Tax Court. The IRS argued that HCA was abusing the tax code. HCA argued that they were following the law as written. The court reviewed the case law going back to 1962, applied the Whiteco factors to the disputed components, and ruled in favor of HCA on the substantial majority of the disputed items.
The decision, Hospital Corporation of America v. Commissioner, 109 T.C. 21 (1997), did three critical things:
First, it confirmed that cost segregation was a legitimate tax strategy. The court explicitly held that taxpayers could reclassify components of commercial buildings as tangible personal property for tax purposes when those components served specific business functions rather than the building itself.
Second, it confirmed that the Whiteco factors were the governing analytical framework. The court applied the six factors from the 1975 Whiteco case to every disputed component and used the analysis to reach its conclusions.
Third, it established a precedent the IRS would have to follow. The IRS had been challenging cost segregation studies. After HCA, those challenges would have to overcome the Tax Court's explicit endorsement of the methodology.
The case was decided in 1997. The IRS officially acquiesced in 1999, through Action on Decision AOD-1999-008. AOD-1999-008 is the IRS document acknowledging that the IRS would not continue to litigate the principle established in HCA. From that moment forward, cost segregation was fully settled law.
By the early 2000s, the IRS was receiving thousands of returns each year that included cost segregation. The IRS needed to standardize how its own examiners evaluated the studies. In 2004, the IRS released the first edition of the Cost Segregation Audit Technique Guide (the ATG).
The ATG was, and remains, the most comprehensive technical guidance the IRS has ever published on cost segregation. It describes the methodology approaches (Approaches 1 through 6) used in studies. It explains what makes a study defensible. It tells IRS examiners what to look for in a quality report. It is, in effect, a manual for both the cost segregation industry and the IRS auditors who review the work.
The first edition was published in 2004. Since then, the IRS has updated it periodically. Notable revisions include 2017 (substantial updates to electrical systems), June 2022 (Inflation Reduction Act adjustments), and the current edition, IRS Publication 5653, dated February 6, 2025. The current edition is 347 pages.
One of the most important characteristics of the ATG is what it does not do. It does not call cost segregation aggressive. It does not call it abusive. It does not suggest it should be limited or curtailed. It is a technical manual that takes the legitimacy of the strategy as a given and focuses entirely on how to do it correctly.
The Tax Cuts and Jobs Act of 2017 (TCJA) made a change that supercharged the economic value of cost segregation. The act introduced 100 percent bonus depreciation for qualifying property placed in service between September 27, 2017, and December 31, 2022, with a phase-down schedule afterward.
Under 100 percent bonus depreciation, qualifying property reclassified by a cost segregation study could be deducted in full in the year the property was placed in service. Not depreciated over 5, 7, or 15 years. Deducted entirely in Year 1.
The Year 1 cash impact was enormous. A property owner doing a study on a new $5 million acquisition might suddenly claim $1.5 million in Year 1 deductions instead of $130,000. At a 37 percent marginal federal tax rate, that was $555,000 in actual federal tax savings in Year 1.
The original TCJA bonus depreciation began phasing down in 2023. From 2023 through 2025, the percentage stepped down (80 percent, 60 percent, 40 percent). Then on January 19, 2025, Congress passed the One Big Beautiful Bill Act (OBBBA), which restored 100 percent bonus depreciation permanently for property placed in service after January 19, 2025.
The OBBBA restoration means that as of right now in 2026, every property owner who commissions a cost segregation study and places qualifying property in service after January 19, 2025, can deduct the reclassified components in full in Year 1. Permanently. Not phasing down. Not changing. The strategy is at full strength.
When was cost segregation first allowed?
The roots trace back to the Investment Tax Credit enacted in the Revenue Act of 1962. The modern methodology was validated by the Tax Court in Hospital Corporation of America v. Commissioner (109 T.C. 21, 1997) and the IRS officially acquiesced in Action on Decision AOD-1999-008 in 1999. The IRS first published its Cost Segregation Audit Technique Guide in 2004. The current edition is Publication 5653, dated February 6, 2025.
Is cost segregation a tax loophole, and what changed under OBBBA?
No, it is not a loophole. Cost segregation is the proper application of MACRS class lives that Congress wrote into the Tax Reform Act of 1986. The IRS publishes 347 pages of guidance on how to perform the work correctly. On January 19, 2025, the One Big Beautiful Bill Act restored 100 percent bonus depreciation permanently for qualifying property placed in service after that date. Every component a study reclassifies into a 5-year, 7-year, or 15-year MACRS class can now be deducted in full in Year 1 rather than spread over the recovery period.
Why does methodology matter so much?
The IRS Audit Technique Guide names Approaches 1 and 2 (detailed engineering from actual cost records or from a current engineering survey) as preferred. Approaches 3 through 6 produce weaker documentation and are more vulnerable in audit. Studies marketed as software-driven or AI-powered typically run Approach 5. They are faster and cheaper but harder to defend if the return gets examined.
It is not a tax loophole. It never was. Loopholes get closed. Cost segregation has been validated by the Tax Court in HCA and confirmed in case after case since. The IRS itself published Publication 5653 to tell its own examiners how to evaluate studies. The methodology is settled law.
It is not aggressive tax planning. It is the proper application of MACRS class lives that Congress wrote in 1986 to the actual components inside your specific building. The deduction is already authorized by the law. A study just claims what the law already allows.
It is not optional, exactly. If you own commercial real estate and you are not doing cost segregation, you are voluntarily paying more tax than the law requires you to pay. That is not strategy. That is leaving money on the table.
The Cost Seg America team has been performing engineered cost segregation studies for more than 24 years. 16,000 studies. 125 IRS audits defended. Zero losses. $0 ever returned to the IRS. Every study uses IRS Approaches 1 and 2. Every study is engineered, not estimated. Flat fee. 100 percent U.S.-based team. The average first-year savings across the 16,000+ completed studies is $438,511. Unlimited audit defense included. Written responses and phone representation. No time limit. No hour cap. No additional fee. Ever. Made in America, by Americans.
The next step on your property takes 30 seconds. Send the property address and the approximate purchase price. The Cost Seg America team sends back a free preliminary proposal within 24 hours. The proposal tells you the estimated Year 1 deduction, the methodology, the timeline, and the flat fee. No obligation either way.
Email: info@costsegamerica.com
Phone: 1-888-365-5023
Online: costsegamerica.com/free-proposal
The story that started with carpet, lighting, and electrical panels in a Tax Court room in 1997 ends with a free preliminary proposal on your specific commercial property in 2026. The legal foundation is settled. The methodology is established. The math is straightforward. The only question left is whether you let a serious firm do the work on your building.